Machine for generating toric surfaces on lenses



Sept. 14, 1926. 1,599,405

L. w. BUGBEE MACHINE FOR GENERATING TORI C SURFACES ON LENSES Filed July 25. 1923 I N VEN TOR. Z ucm/v kit-B06065,

ATTORNEYS Patented Sept. 14, 192 i UNITED STATES LUOIAN w. Brianna, or INDIANAPOLIS,

PATENT OFFICE.

INDIANA, ASSIGNOR; BY MES NE ASSIGN- MEN'IS, TO CONTINENTAL OPTICAL CORPORATION, OF NEW YORK, N.. Y.', A 003- PORATION OF DELAWARE.

MACHINE FOR GENERATING TORIQ SURFACES N LENSES.

Application filed July 23,

The object of this invention is to improve the construction and operation of apparatus ,for enerating toric lenses, whereby several advantages are obtained and wherein there is a grinder having a grinding periphery for grinding and determining the curvature of the lens in one principal meridian and a lens holder pivotally mounted and oscillatable tangentially of the grindor with a radius of oscillation such as to predetermine the curvature of the lens in the other rincipal meridian.

In t e apparatus shown herein the trans: verse curvature of the periphery of the grinder determines the meridional curvature and the radius of oscillation of the lens holder as the grinder determines the'equatorial curvature.

One feature of the invention consists in having a radially adjustable lens holding bar whereby the equatorial curvature of; the lenses is determined merely by the radial adjustment of the lens holding bar. When a spotting wheel or the like is usedin an apparatus of this kind to vary the equatorial curvature of the lens, it requires the replacing of the spotting wheel by another spotting wheel, and, therefore, a considerable stock of spotting wheels must be carried. That expense and annoyance is made unnecessary by this simple improvement, where a small lens holding bar is adapted, by radial adjustment, to determine any distances of equatorial curvatures that may be desired. Insuch apparatus the meridional curvature is determined by the transverse peripheral form of the grinding wheel, the same as in prior apparatus for grinding toric lenses.

the plane of the grinder and is non-rotary and has no other movement than said oscil-q latable movement. This movement is preferably effected by hand.

This apparatus ispartic'ularly well adapted where toric lenses areto be ground .for single prescriptions, and it is also very advantageous to, small and retail opti'cians and optical concerns where the lenses are groun as single prescriptions. Heretofore the optician or optical concerns-havev been re-- quired to have in stock quitea large number of tools,- one for each possible combination that may be required-in the business. Hence,

The lens holdin means is oscillatablein 1923. Serial 110. 653,367.

this greatly cheapens the equipment foropings and the following description and claims.

In the drawings, Fig. 1 isa side elevation of said machine illustrating this invention, parts of the grinder being broken away and the lens block being shown in different posiv o o 0 tlons assumed while the lens 1s being ground.

Fig. 2 is a plan view of the machine.

'In the machine herein shown for the purpose of illustrating the general nature of this invention, there is a table or base plate 10 on which is mounted a plate 11 carrymg two bearing posts 12 for an arbor shaft 5 13, on one end of which a grinding wheel 14 is removably secured and which is driven by apulley 15 secured on the arbor 13 between the two bearings 12.

There is also shown herein a truing device which constitutes no necessary part of this invention, but which consists of an adjustable plate 20 mounted on the main plate or table 10 and with a key 21 onthe under side projecting in the keyway I22, and which plate is angularly adjusted by bolts 3 extending up from the main plate 10 though slots 24 in the plate 20. The plate 20 carries a post 25 in which is mounted a pointer or centering pin 26.

There is also a plate 30 mounted on the main plate-10 and having on its under-side. v

nut 35. There is a nut 38 for holding said 'fulcrum pin 34 in said post 33 but so the pin can' turn. The lens holding" bar 40 is thus held in the same plane as the grinder 14, and, so that a lens blank 42 secured on the end of said holder 40 may engage'the Y periphery of the grinder, as shown.

- The lens holding bar has a longitudinal slot through which the fulcrum 34 extends, whereby the lens holder is adaptable to use with grinding wheels of varying 'ldiameters,

but the main advantage is the radial adjustability of the lens holding bar for varying the radius of the equatorial curvature of the lenses. All that is necessary for changing the apparatus to vary the equatorial curvature of the lense is to loosen the nut 35,

slide the lens holder longitudinally to a position which gives the radius for the desired equatorial curvature, and then tlghten the nut.

' On the lens holding bar 40 a scale of nu- 1 and by adjusting the position of the bar to inerals 43 is marked representing diopters,

bring any part of said scale intoregistry with the mark 44 on the post 33 or some other stationary indicator, one is enabled quickly to adjust the lens holding bar to obtain any desired equatorial curvature. The lens blanks are secured by pitch or the like on lens block 45 which has a hub-like extension projecting into a round aperture in the end of the lens holder where it is secured by a set screw 46. q

-The meridional curvature is determined by the transverse surface of the periphery of the grinding wheel in this machine as in other toric generating machines. In operating the apparatus, the plate 30 carrying the lens holding bar must be set so as to bring the lens blank in contact with the periphery of the grinding wheel. This adjustment of the plate will be necessary whenever the lens holding bar-isadjusted, and it is also necessary when there is a change of grinding wheel or when it is necessary to change the position of the plate 30 toac commo'date the apparatus with the wear or reduction in diameter of the grindin wheel.

The plate 30 isheld'in adjusted posltion by.

' thereofin the plane of the grinder andthis the manual thepperator. In operation, a lens is placed on the end of oscillation is preferably manual so'that the lens can be properly fed to the wheel by operation and observation of thelens holder :40, andsaid lens holder is setat the desired diopter and the grinding wheel rotated, and the lens holder 40 brdught to either one of the dotted line positions shown in Fig.1, where the grinder will begin to grind thelens-and then the operator continually but slowly oscillates the-lens holder from one of the dotted line positions to the other. This is done by the handle 41. One movement of the lens holderwill roughgrind the lens. Then the operator oscillates the lens holder back and forth throughout its entire are several times. .thus rapidly bringing the lens in touch with the grinder in order to grind out any lines in the lens and perfect and finish the grinding thereof.

43 slidable anda'djustable longitudinally of the lens bar 40, as shown in Fig. 1. This is desirable because the lens blocks 45 are of diiferent thicknesses and so are the lens blanks 42,'and their variation in thickness is compensated for by corresponding adjustment of the sliding scale bar 43. As seen in Fig. 1 the scale bar has a key operating in a dovetail groove in the lens bar 40. In this way the apparatus canbe set with absoluteaccuracy.v

Also for varying the axes of the toric lens according to an need .,or prescription; a scale 50 is provi ed on the end of the lens bar 40, as seen in Fig. 2, with whicha mark 51 on the lens block 45 is adapted to regis ter. By slightly turnin the lens block 45 one way 'or-the othenthe desired angular adjustment of the lens is attained, whereby the lens when ground will have the axes called for by the prescription.

The details of the construction herein shown to illustrate the invention may be varied without departing from the spirit of the invention, as expressed in the claims.

The invention clalmed is:

1. In a machine for generating toric surfaces onlenses, a fixed rotary grinder with its. periphery curvedjtransversely so asto determine the curvature of the lens in one principal meridian, a lens holder oscillatable in the plane of the grinder for moving the lens to and past the grinding radius ofv the grinder a relatively fixed fulcrum for said lefis holder, and means permitting v varying the radius of oscillation of thelens holder to dpredetermine the arc'of travel past the grin er and thereby the curvature of the lens in the other principal meridian.

2. In a machine for generating toric surfaces on lenses, a fixed rotary grinder with its periphery curved transversely so as to determine the curvature of the lens in one principal meridian, a lens holder oscillatable in the same plane as the grinder .for

moving the lens to and past the grjndin radius of the grinder and a relatively fixe fulcrum for said lens holder on which. the

lens holder is radially adjustable permitting varyin the radius of oscillation of the lens to pre etermine the arc of travel past the inder. and thereby the curvature of the ens in the other principal meridian.

3. In a machine for generating toric surfaces on lenses, a rotary grinder with its periphery shaped in cross section so'astodetermine the meridional curvature of the lens, a longitudinally slotted bar for holding the lens on the .end thereof against the 70 It is preferable to make the diopter scale said t-atable fulcrum pin mounte parallel with the axis of the grinding wheel,

periphery of sai grinder, a fulcrum pin extending through said slot, stationary means in :which said fulcrum pin is mounted so that it will oscillate, means for clamping the lens hold-' ing bar on said fulcrum pin when adjusted, and a handle for oscillating thelens holding bar in the same plane as the grinder.

4. A machine for generating toric surfaces on lenses including a base-plate, a

grinding wheel, means mounted on said plate for supportin the grinding wheel, means for rotatin t e grinding wheel, the periphery of said grinding wheel being shaped in cross section so as to form the meridional curvature of the lens, a post mounted 0n said base plate 'and adjustable toward and away from said grinder, means for fastening it in adjusted (position, a romachine I for e'nerating toric sur- 'ng a base plate, a

meridional curvature of the lens, 'a post mountedon said base plate and adjustable 4o tatable fulcrum pin mounte thereby tangentially toward and away from said grinder, means for fastening it in adjusted osition, a roin said post parallel with the axisof the grinding wheel, a lens holding bar with a longitudinal slot in it through which said fulcrum pin: extends, and means for clamping said bar on said pin when adjusted, whereby said bar may be oscillated .toimove a lens carried into and contact with and past the grinding radius of the grinding wheel, said lens holding bar having a diopter scale thereon and said post'havmg an indicating mark with which said diopter scale is adapted to register, whereby-the lens holding bar can be readily set to' obtain the desired equatorial curvature of the lens.

6. In amachine for generating toric surfaces on-lenses, a rotary grinder with. its periphery a termine the curvature of the lens in one principal meridian, a lens holding barescillabl for moving the lens to and past in" said post past the grinding radius of the grinding wheel, means mounted on' said curved transversely so as to dethe grinding radius of the grinder, a relatively fixed fulcrum for said lens holding bar, means permitting varying the radius of oscillation of the lens holder to predetermine the arc of travel past the grinder and thereby the curvature of the lens in the other principal meridian, and a lens holding block in the end of said; bar which'is angularly. adjustable for varying the axis of the lens;

7. In a machine for generating .toricsur- I I faces on lenses, a rotary grinder with its periphery curved transversely so'as to determine the curvature of the lens in one principal meridian, a lens holding bar longitudinally slotted, a relatively fixed fulcrum extending through said slot in the lens holding bar .so that the lens holding bar may be oscillatable for moving the lens to'and' past the grinding radius of the grinder and be radially adjustable for determining the are of travel past the grinder and thereby the curvature of the lens in the other principal meridian, and a lens holding block in the end of said bar which is angularly adjustable for varying the axis of the lens.

8. In a machine for 'generating-to'ric surfaces on lenses, a rotary grinder with its periphery curved transversely to determine the curvature of the lens in one principal meridian, a lens holding means, a fulcrum for said lens holding means located on the same side of the grinder as the lens holding means and which enables the lens holding means to be oscillated for moviiig the lensto and past the grinding radius of the grinder, and means permitting varying-the radius of oscillation of the lens holder to predetermine the arc of travel past the rinder 'and thereby the curvature of the ens in the other principal meridian.

9. Ina machine for generatingtoric surfaces on .lenses, a rotary grinder with its periphery curved'so as to be concave versely to generate the desired curvature of the lens in one principal meridian, a lens holding -means, a fulcrum for said lens trans-- holding. means which enables the latter to be oscillated in the plane of 'the grinder for moving the lens to and past the 'rinding lens, and means permittin radius of such oscillation of t e lens hdlding means, to determine the arc of travel past the grinder'and thereby the curvature of the lens in the other principal meridian.

In witness whereof, I have hereunto affixed my signature.

LUCIAN w. BueBEn 'radius of the grinder for line grin 'ng the varyim the 

